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room addition and adding heat

josephcjosephc Posts: 14Member
we are having a 16ft by 17 ft by 8 ft high tv room addition added onto our home. I have not gotten a firm estimate of required BTUs though the range has been anywhere from 8800 to 12000. Any advice/rules of thumb/direction is appreciated on the calculation (I checked the slantfin site and am trying to use it); located in upstate ny.

my other question is the addition of the heat source. I have a two pipe vapor system/gravity return. My boiler is already large and there is room for more edr. Do most jobs of this scope add on a classic radiator like the rest found in the home or do something else like a steam baseboard or a hydronic loop with circulator? Based on my discussion with builder and the plumber it looks like up to me to get the radiator and give direction.

the existing main and returns have 1 inch supply and 3/4 inch return taps from radiators removed in the past. My initial thoughts are a radiator of 60-70 edr max would give more than enough btu and would be close to limit supplied by the 1 inch pipe. Am I close to knowing what I'm doing?


  • New England SteamWorksNew England SteamWorks Posts: 1,039Member
    My advice is to pipe in steam if at all possible. Adding a hot water loop introduces a lot of unneeded expense and complexity. But, that's likely the route they will push you because it is their comfort zone.
    Serving Rhode Island & Eastern Massachusetts
    Old Houses & Steam Heat Our Specialty
  • JackJack Posts: 1,013Member
    Look at a Rinnai Energysaver EX-11. Modulates from 5500-11000btu. 2.5" hole for the supplied vent. Very reliable.
  • SteamheadSteamhead Posts: 11,967Member

    My advice is to pipe in steam if at all possible. Adding a hot water loop introduces a lot of unneeded expense and complexity. But, that's likely the route they will push you because it is their comfort zone.

    This. We've done it, and as long as you stay true to the Dead Men's pipe and radiator sizing, it works great.
    All Steamed Up, Inc.
    "Reducing our country's energy consumption, one system at a time"
    Steam, Vapor & Hot-Water Heating Specialists
    Oil & Gas Burner Service
    Baltimore, MD (USA) and consulting anywhere.
  • ZmanZman Posts: 4,067Member
    Your heat loss estimates look high.
    The whole key to this is to get the right steam guy.
    The plumber that want's you to provide direction is a huge red flag. He probably is not the right guy for the job.
    This book will help you understand how to find the right contractor.
    "If you can't explain it simply, you don't understand it well enough"
    Albert Einstein
  • BrewbeerBrewbeer Posts: 441Member
    Seems to me that if staying with steam, you need to calculate the ratio of ERD to heatloss in the other existing rooms, them size your radiation in the new room keeping this ratio in mind. Also, heat loss in the spaces that will be adjoining the new room, will decrease.
    Hydronics inspired homeowner with self-designed high efficiency low temperature baseboard system and professionally installed mod-con boiler with indirect DHW. My system design thread:
    System Photo:
  • brandonfbrandonf Posts: 58Member
    Investing in really good insulation will help lower that heat loss. You can go with a vintage radiator or you can buy brand new although they are very pricey. But nothing beats the comfort.
  • ThomasMiller1ThomasMiller1 Posts: 14Member
    Unlike resistance heat, which uses electric elements to generate heat, a minisplit heat pump (MSHP) moves heat from one location to another using refrigerant, a compressor, heat exchangers, and an expansion valve. During the summer, an MSHP moves heat from inside the building to the outside. During the heating season, the unit operates in reverse, capturing heat from the outside air and moving it into the home. Since the heat source for these units is air, they are commonly referred to as air-source (or air-to-air) heat pumps.

    The idea that heat can be extracted from outdoor winter air can be a bit perplexing, but it is this same refrigeration principle that allows a fridge or freezer to use room-temperature air to cool its inside. As long as the temperature of the refrigerant is below the outdoor air temperature, it will be able to absorb heat. This is accomplished by blowing the warmer outdoor air past a heat exchanger containing the refrigerant. The refrigerant changes to a gas as it is heated, and its pressure and temperature are increased by a compressor. This superheated gas is then transported to a heat exchanger in the indoor unit. A fan in the unit circulates indoor air past the heat exchanger to heat the inside of the home. As the heat is released, the refrigerant condenses and is returned to the outdoor unit. An expansion valve reduces the pressure of the liquid at the outdoor unit, and the refrigerant becomes a gas again as it absorbs heat from the outdoor air.

    Most MSHP systems are ductless, making them a versatile option for retrofits. Heated or cooled air is distributed via a fan in the indoor unit, which may be mounted on a wall, on a floor, or in the ceiling. Since airflow is resistant to constrictions, such as doorways, these units have the greatest impact in open spaces that permit broad distribution. In homes that are heavily partitioned, multiple indoor units may be needed to provide comfort throughout the home. For some applications, small ducted indoor units may be used.

    Because ductless MSHPs are point sources of heating and cooling, this often makes them best suited to reducing the energy demands of a central heating system rather than replacing the system entirely. In a new, well-insulated and sealed home, many designers combine heat pumps with strategically located electric resistance heat in bathrooms and other critical areas to avoid the need for a central heating system.
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